1. Field of Invention
The present invention relates to submersible transport and storage systems. In particular, it relates to a lightweight towed submerged water transporter and storage system for liquids and solids, which employs an inflatable hull with optional air and liquid storage bladders used not only to adjust buoyancy, but to allow the simultaneous transport of different solids and liquids.
2. Description of Related Art
Various submersible transport and storage systems are known in the art. Blanchard et al, U.S. Pat. No. 5,899,637 issued May 4, 1999 provides an offshore production and storage facility and method of installing the same employing a concrete barge having oil storage tanks secured to its deck that is towed to an oil production site where it is sunk to the sea bottom. It is of heavy construction and is towed on the water until sunk in position via controlling the pressure of air in the storage tanks. It is not designed as a lightweight backhaul carrier to reduce transportation costs, when empty and shipped to the site.
Agnew, U.S. Pat. No. 6,260,501 issued Jul. 17, 2001 discloses a submersible apparatus for transporting compressed gas. It has a plurality of spools, each having a central bore and a long continuous length of relatively small diameter line pipe for holding compressed natural gas wound about each spool with an inner end terminating in the bore and an outer end terminating at the outer surface of the spool stored within a tank having a thin housing to store the spools vertically therein. The tanks are usually towed underwater at a depth via ballast means, and the spools are surrounded by a non-corrosive fluid to support a pressure differential to greatly reduce the structural requirements of the housing.
Kitabayashi, U.S. Pat. No. 3,999,499 issued Dec. 28, 1976 discloses a surface vessel driven and controlled submarine cargo transport. The device employs a cylindrical thnk-like submarine hull, which acts as a cargo carrier, and carries a propulsion element, which is power driven through a power supply from a surface vessel through a power transport member interconnection. Ballasting means are included to control the elevation such that the vessel stays near the surface.
Schirtzingel, U.S. Pat. No. 4,108,101 issued Aug. 22, 1978 discloses a towing system for cargo containers using a semi-rigid boom extending from the stern of a towing vessel to hold the nose of the container at a level below the wake of the towing vessel.
Giannesini, U.S. Pat. No. 5,354,151 issued Oct. 11, 1994 discloses a system for loading at sea employing a submersible conveying structure and anchoring device, which includes a loading system adapted to lie on a sea bed. A buoy holds the conveying structure hear the surface, unless there is ice or other surface obstructions, wherein the buoy and conveying structure is pulled below the surface until the surface obstructions are no longer present.
Mumford, U.S. Pat. No. 2,371,404 issued Sep. 15, 1942, discloses a towable submersible container containing ballonettes to adjust buoyancy. The container has bulkheads forming a central cargo hold and two end compartments containing the ballonettes to adjust the buoyancy. It may include an expandable rubber liner for hull reinforcement.
Hashemi, U.S. Pat. No. 3,648,635 issued Mar. 14, 1972 discloses a marine transport for moving bulk quantities of goods in a submarine hull having ancillary surface accommodations for a crew connected to the submarine via an elongated fin extending to the surface. It is power driven with the submarine hull cargo container submersible to avoid ice and other surface obstructions, which could damage the hull.
Anders, U.S. Pat. No. 3,902,440, issued Sep. 1, 1975, is an underwater vehicle which may be towed or self powered to travel beneath the water to avoid obstructions and aid in ocean mining and underwater exploratory activities. It has a submerged weight of the frame controlled by buoyancy tanks to maintain the vehicle at the desired bottom elevation.
Martin, U.S. Pat. No. 6,796,379 issued Sep. 28, 2004 is drilling waste handling method and apparatus for storage and transport of drilling waste. A number of storage containers are anchored to the sea bed by means of anchors and cables. These containers are marked with buoys and have adjustable buoyancy. Drilling waste is macerated on board a drilling vessel and pumped via conduits into the containers. Once the containers are full, they are towed to an onshore waste recycling facility and then returned to the drilling vessel for reuse. Usually the containers employ internal agitators to rotate the containers in response to sea currents.
Fontana, U.S. Pat. No. 7,185,705B2 issued Mar. 6, 2007 discloses a system and method for recovering return fluid from sub sea well bores using submersible containers, which are expandable or collapsible, such that they inflate or expand when filled with fluid. Alternatively, they are relatively inflexible vessels. Buoyant members provide a buoyancy force for raising the transport device towards the surface once the drilling operation is completed. It allows for the recovery of return fluids for treatment and reuse. Fluids are typically transported and collected via a stand pipe connecting the surface operations with the subsurface containers.
None of the above references provides a lightweight towed submerged water transporter and storage system for liquids and solids, which employs a lightweight longitudinally reinforced hull with optional air and liquid storage bladders used not only to adjust buoyancy, but to allow the simultaneous transport of different solids and liquids for unloading or storage at a delivery point or on a back haul without cross-contamination.